导　　师： 陈兆平;靖元孝

学科专业： G1001

授予学位： 硕士

作　　者： ;

机构地区： 华南师范大学

摘　　要： 以不同苗龄的香根草(vetiveria zizanioides,英文名vetiver)为材料,进行不同深度的淹水处理,研究了香根草在淹水条件下的形态和生理变化及其抗涝性.主要的研究结果如下:1.盆栽香根草实验表明:全淹状态下香根草虽然停止生长,但仍能保持较长时期的存活,夏季为3个月左右,冬季为5个月左右.退水后,香根草可以逐渐回复生长.2.淹水对香根草根长有明显的抑制作用,茵龄越小淹水越深,抑制越强烈.淹水条件下,香根草根毛显著减少,根系颜色随淹水深度增加而变深.但淹水对香根草根系生物量的影响则有所不同,长期淹水材料的测定结果表明,适度的淹水可以促进根系生物量的增加,深度淹水则抑制根系生物量的增加.3.淹水条件下,香根草地上部分的变化也表现出一定的适应性.适度淹水刺激香根草分蘖增生,地上部分生物量与对照相比无明显差异,而深度淹水则抑制香根草分蘖和地上部分生物量.此外,淹水条件下香根草的株高低于对照组.4.淹水组香根草的净光合速率、气孔导度、蒸腾速率及叶绿素含量都超过了对照组,而且随淹水深度增加而升高.淹水条件下,老根活力呈先上升后下降的趋势,两周后淹水组开始长出大量新根,而且新根的活力高于对照组根活力.5.对香根草抗涝性指标的测定表明,淹水使香根草cat活性升高,sod活性基本不变,mda含量稍有积累,但质膜透性没有明显变化.总之,在淹水条件下香根草在形态和生理上都出现了适应性的变化,抗涝性极强,具有两栖特性,可考虑在水库库岸、河岸等水位易波动地区种植. Morphological and physiological responses of vetiver to flooding and its resistance to flooding were studied. The results are as follows: 1. Potted plant assaying showed that vetiver could survive for 3 months in summer and 5 months in winter when they were fully flooded, and vetiver could resume to grow gradually after removal of flooding. 2. Flooding inhibits the elongation of vetiver roots, and the younger seedlings were,the severer inhibition was. On the condition of flooding, the root hair of vetiver was decreased significantly and the color of root system became black. Moreover, moderate flooding increased biomass while deeper flooding decreased it. 3 At the situation of moderate flooding, the tillers increased and the biomass of up-grounded parts has no significant difference. However, the tillers and the biomass of up-grounded parts were all inhibited by deeper flooding. In addition, the height of vetiver was influenced by flooding. 4. The chlorophyll content, net photosynthetic rate , stomata conductance and transpiration rate of flooded vetiver were higher than those of control group. On the flooding condition, the vigor of the old root system rose first and fall then. After two weeks, the flooded vetiver developed a great deal of new roots and the vigor of new roots was higher than that of control group. 5. When vetiver was flooded, CAT activities increased greatly and MDA content rose slightly while SOD activities and the electrolyte leakage have no obvious differences between flooding group and control group. On the whole, vetiver showed much adaptation to flooding in morphology and physiology and had strong resistance to flooding. So vetiver is an amphibious plant and could be planted along river banks and reservoir banks where water levels fluctuate .

关 键 词： 香根草 生物量 净光合速率 蒸腾速率 气孔导度 叶绿素 质膜透性

分 类 号： [Q949.7]

领　　域： [生物学]